Neural feedback assisted DBS

Abstract

Methods and systems for using sensed evoked neural responses for informing aspects of neurostimulation therapy are disclosed. Electrical signals may be recorded during the provision of electrical stimulation to a patient's neural tissue. The electrical signals may be processed and analyzed using one or more classification criteria to determine if the electrical signals contain a neural response of interest. Examples of such neural responses include evoked neural responses that are oscillatory and/or resonant in nature. If the electrical signals include such responses of interest, one or more features may be extracted from the signals and used as biomarkers for informing aspects of neurostimulation therapy, such as directing lead placement, optimizing stimulation parameters, closed-loop feedback control of stimulation, and the like. Various methods and systems described herein are particularly relevant in the context of multi-site stimulation paradigms, such as coordinated reset neuromodulation.

What is claimed is: 
     
       1. A medical device, comprising:
 an implantable pulse generator (IPG) configured for implantation in a patient and comprising a plurality of electrode nodes, each electrode node configured to be coupled to an electrode configured to contact a patient's brain tissue; and 
 control circuitry configured to:
 control stimulation circuitry to issue stimulation at a first one or more of the plurality of electrode nodes, 
 record an electrical signal at a second one or more of the plurality of electrode nodes, 
 classify the recorded electrical signal according to one or more classification criteria indicative of evoked resonant neural activity (ERNA) to determine if the recorded electrical signal contains ERNA, 
 if the recorded electrical signal does contain ERNA, extract one or more features of the ERNA, 
 adjust stimulation based on the one or more features, and 
 if the recorded electrical signal does not contain ERNA, make no adjustment based on the signal. 
 
 
     
     
       2. The device of  claim 1 , wherein the one or more classification criteria comprise one or more peaks or troughs with a prominence exceeding a predetermined threshold value or values. 
     
     
       3. The device of  claim 1 , wherein the one or more classification criteria comprise a number of peaks meeting or exceeding a predetermined threshold number of peaks within a predetermined time window. 
     
     
       4. The device of  claim 1 , wherein the one or more classification criteria comprise one or more peaks with amplitudes meeting or exceeding a predetermined amplitude threshold. 
     
     
       5. The device of  claim 1 , wherein the one or more classification criteria comprise one or more components within a range of predetermined frequencies and exceeding one or more predetermined thresholds. 
     
     
       6. The device of  claim 1 , wherein determining if the recorded electrical signal contains ERNA comprises assigning a confidence value that a neural response of interest is present and rejecting the recorded electrical signal unless the confidence value meets or exceeds a predetermined threshold. 
     
     
       7. The device of  claim 1 , wherein the one or more features of the ERNA comprises one or more of a band power, a peak power, a full width at half max (FWHM), or a decay constant. 
     
     
       8. The device of  claim 1 , wherein the one or more features of the ERNA comprises one or more of a peak amplitude or a number of peaks. 
     
     
       9. The device of  claim 1 , wherein the recorded electrical signal is a time domain signal, and wherein the control circuitry is configured to determine a frequency domain signal corresponding to the time domain signal. 
     
     
       10. The device of  claim 9 , wherein the step of classifying the electrical signal is performed on the frequency domain signal. 
     
     
       11. The device of  claim 9 , wherein the step of extracting one or more features of the ERNA is performed on the frequency domain signal. 
     
     
       12. The device of  claim 10 , wherein the step of extracting one or more features of the ERNA is performed on the time domain signal. 
     
     
       13. The device of  claim 9 , wherein determining if the recorded electrical signal contains ERNA further comprises determining if one or more relative band powers in one or more predetermined frequency ranges of the frequency domain signal meet or exceed one or more predetermined thresholds. 
     
     
       14. A method for providing stimulation to a patient's brain, wherein the patient is implanted with one or more electrode leads comprising a plurality of electrodes, the method comprising:
 issuing stimulation at a first one or more of the plurality of electrodes, 
 recording an electrical signal at a second one or more of the plurality of electrodes, 
 classifying the recorded electrical signal according to one or more classification criteria indicative of evoked resonant neural activity (ERNA) to determine if the recorded electrical signal contains ERNA, 
 if the recorded electrical signal does contain ERNA, extract one or more features of the ERNA, 
 adjusting stimulation based on the one or more features, and 
 if the recorded electrical signal does not contain ERNA, making no adjustment based on the signal. 
 
     
     
       15. The method of  claim 14 , wherein the one or more classification criteria comprise one or more peaks or troughs with a prominence exceeding a predetermined threshold value or values. 
     
     
       16. The method of  claim 14 , wherein the one or more classification criteria comprise a number of peaks meeting or exceeding a predetermined threshold number of peaks within a predetermined time window. 
     
     
       17. The method of  claim 14 , wherein the one or more classification criteria comprise one or more peaks with amplitudes meeting or exceeding a predetermined amplitude threshold. 
     
     
       18. The method of  claim 14 , wherein the one or more classification criteria comprise one or more components within a range of predetermined frequencies and exceeding one or more predetermined thresholds. 
     
     
       19. The method of  claim 14 , wherein determining if the recorded electrical signal contains ERNA determining a frequency domain signal corresponding to the time domain signal. 
     
     
       20. The method of  claim 19 , wherein determining if the recorded electrical signal contains ERNA further comprises determining if one or more relative band powers in one or more predetermined frequency ranges of the frequency domain signal meet or exceed one or more predetermined thresholds.